There are some differences that should be considered when choosing the data retrieval method used in the MIDlet, depending on the sensor used.
Using condition listening is recommended for slow sensors such as battery charge level, charger state and network field intensity because with these sensors the condition evaluation is only triggered when the value changes.
With data listening mode the value is sent with some constant rate even if the value has not changed. With fast sensors, such as accelerometer, the performance difference between condition and data listening is not so significant.